Dear Sterioma,
Great to welcome another devotee of the black art. Like Lee Shively, I too had a flashback to my first processed film (FP4 in Promicrol, I think) some 30 odd years since. I've had my share of disasters too! Just a shame this forum wasn't around in 1973. Speaking for myself, I,ve always found that inversion agitation works better than the twiddle stick, but that's the beauty of this craft; ask a million different photographers and you'll get a million different answers. Enjoy yourself, regards, BLIGHTY